Dielectric strength test of transformers
The electric transformer is a static device
that converts electric energy from one circuit to another circuit without any
direct electrical connection. Transformer works on Faraday mutual induction.
Simply it is used to increase and decrease the voltage.
we need
to know the historical backdrop of the transformer, we need to return long
during the 1880s. Around 50 years before that in 1830 the property of induction
was found, and this is the working guideline of the transformer. Later the
transformer configuration was improved bringing about more productivity and
lesser size. Progressively the enormous limit of transformers in the scope of a
few KVA, MVA appeared. In the year 1950, 400KV electrical force transformer was
presented in high voltage electrical force framework. In the mid-1970s, unit
rating as extensive as 1100 MVA was delivered. Different producers made 800KV
and considerably higher KV class transformers in the year 1980
Transformer oil is a mineral-based oil that is
regularly utilized in transformers for its compound properties and dielectric
strength. This oil in your transformer goes about as a cover and a cooling specialist.
Over a long time, the oil will corrupt bringing about the potential for issues
and expensive fixes. With an appropriate safeguard support program. The nature
of your transformer oil will impact its protection and cooling properties.
Under ordinary working conditions, a negligible breakdown of oil quality will
happen from oxidization and pollution.
Testing your transformer oil ought to be
essential for your yearly safeguard support program. Testing the oil will
assist with deciding when remedial measures are required. Introductory testing
will build up a benchmark for examination and yearly testing will plot any
progressions inside in your transformer. Dielectric breakdown: Dielectric
strength is a proportion of voltage the oil will protect against. Numerous
foreign substances direct power in a way that is better than oil accordingly
bringing down the dielectric breakdown.
The
dielectric strength of transformer oil is otherwise called the breakdown
voltage (BDV) of transformer oil. Breakdown voltage is estimated by seeing at
what voltage, starting strands between two terminals drenched in the oil,
isolated by a particular hole. Low estimation of BDV demonstrates the presence
of dampness substance and leading substances in the oil.
For estimating BDV of transformer oil,
convenient BDV estimating unit is by and large accessible at the site. In this
pack, oil is kept in a pot in which one set of terminals are fixed with a hole
of 4mm between them. Presently gradually rising voltage is applied between the
cathodes. The pace of rising voltage is controlled at 2 KV/s and notice the
voltage at which sparking begins between the terminals. That implies at which
voltage dielectric
strength of transformer oil between the anodes has been separated.
This estimation is taken three to six times in
a similar example of oil, and we take the normal estimation of these readings.
BDV is a significant and famous trial of transformer oil, as it is the
essential marker of the strength of oil and it tends to be handily completed at
the site.
Dry and clean oil gives BDV results, better
than the oil with wetness content and other directing pollutants. Least
breakdown voltage of transformer oil or dielectric
strength of transformer oil at which this oil can securely be utilized in a
transformer is considered as 30 kV.
There are two principal kinds of transformer oil utilized in transformers:
Ø Paraffin based transformer oil
Ø Naphtha based transformer oil
Naphtha oil is more effectively oxidized than
paraffin oil. In any case, the result of oxidation – for example ooze – in the
naphtha oil is more dissolvable than the muck from the paraffin oil.
Subsequently, the sludge of naphtha-based oil isn't accelerated in the lower
part of the transformer. Consequently, it doesn't block convection
dissemination of the oil
Even though Paraffin oil has a lower oxidation
rate than Naphtha oil, the oxidation item (slop) is insoluble and encouraged at
the lower part of the tank. This muck goes about as a deterrent to the
transformer cooling framework. Another issue with paraffin-based oil that the
broke up waxes within it can prompt a high pour point. Even though this isn't
an issue in hotter atmosphere conditions. Despite the inconveniences referenced
above, paraffin-based oil is still usually utilized in several nations because
of its high accessibility. To know more about The
dielectric strength of transformer oil you can visit Hering VPT.
For more info dielectric strength of transformer oil in kv/mm.
Some properties
of transformer oil ought to be considered to decide the usefulness of the oil.
The properties of transformer oil are:
1.
High dielectric breakdown
2.
Low consistency - protection from
continuous disfigurement by shear pressure or tractable pressure.
3.
Very much refined and liberated
from materials that they may consume the metallic parts
4.
Be liberated from dampness and
polar ionic or colloidal foreign substances
5.
To have a low pour point (the
temperature at which a fluid lost its stream qualities become semi-strong)
6.
Low glimmer point (the most
reduced temperature at which a fluid disintegrates to make the ignitable
combination in the air).
Media Contact
Company Name: Hering VPT
Contact Person: Detlev Bastek
Email: Send Email
Phone: +49 9831 8834666
Address: D-91550
Dinkelsbuhl,Ernst-Schenk-Str.10
Country: Germany
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